package com.base.utils;

import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
/**
 * 数据加密解密处理
 * @author Administrator
 *
 */
public class QuickSDKDesUtil {
	
	//正则表达式，用于匹配
	private final static Pattern pattern = Pattern.compile("\\d+");
 
	private final static String charset="utf-8";
 
	//加密处理
	public static String encode(String src,String key) { 
		try {
			//得到一个指定的编码格式的字节数组，Linux和windows默认的编码格式不同，所以要指定特定的编码
			byte[] data = src.getBytes(charset);
			byte[] keys = key.getBytes();
			StringBuilder sb = new StringBuilder();
			for (int i = 0; i < data.length; i++) {
				//结合key和相应的数据进行加密操作,ofxx的作用是补码，byte是8bits，而int是32bits
				int n = (0xff & data[i]) + (0xff & keys[i % keys.length]);
				sb.append("@" + n);
			}
			return sb.toString();
		}catch (UnsupportedEncodingException e){
			e.printStackTrace();
		}
		return src;
	}
 
	//解密处理
	public static String decode(String src,String key) {
		if(src == null || src.length() == 0){
			return src;
		}
		//正则表达式字符串匹配
		Matcher m = pattern.matcher(src);
		
		List<Integer> list = new ArrayList<Integer>();
		//find方法(部分匹配):尝试去发现输入串中是否匹配相应的子串
		while (m.find()) {
			try {
				//返回匹配到的子字符串
				String group = m.group();
				list.add(Integer.valueOf(group));
			} catch (Exception e) {
				e.printStackTrace();
				return src;
			}
		}
		
		//如果有匹配的字符串
		if (list.size() > 0) {
			try {
				byte[] data = new byte[list.size()];
				byte[] keys = key.getBytes();
				//相对于加密过程的解密过程
				for (int i = 0; i < data.length; i++) {
					data[i] = (byte) (list.get(i) - (0xff & keys[i % keys.length]));
				}
				return new String(data, charset);
			} catch (UnsupportedEncodingException e){
				e.printStackTrace();
			}
			return src;
		} else {
			return src;
		}
	}
}